Field of the Invention
The present invention relates to a corrugated steel pipe, and more particularly, to a corrugated steel pipe in which a fluid smoothly flows, the corrugated steel pipe is not easily ruptured by pressure which increases therein, and the corrugated steel pipe is rapidly manufactured, a manufacturing period and manufacturing cost are reduced.
Discussion of the Related Art
Concrete pipes are primarily used to guide movement of a fluid on roads, harbors, sewage treatment plants, and the like. When the concrete pipes are transported and handled, heavy equipment is required to be input due to an increase in weight and volume of a vehicle body and a construction period is lengthened due to an increase in connector together with a decrease in workability caused by installation and uninstallation of a mold during construction, and the concrete pipes have seasonal restrictions due to freezing of base cement linking connectors.
Further, the concrete pipes are excellent in strength, but weak to impact applied from the outside, and as a result, the concrete pipes are easily cracked or in severe cases, the concrete pipes are damaged.
Accordingly, in recent years, a steel pipe is used, in which a galvanized steel plate is rolled in a spiral shape and a rolled boundary is lock-seam connected and the quantity of the steel pipes has been gradually increased.
The steel pipe has a simple shape in which the steel pipe is rolled in the spiral shape and the boundary is lock-seam connected and all residual parts other than the lock-seam connection portion is smooth. The steel pipe significantly solves the problem of the concrete pipe, but since an inner diameter part of all residual parts other than the lock-seam connection portion is not curved and flat, the strength significantly deteriorates, and as a result, the steel pipe cannot be widely used for a purpose of guiding transfer of a fluid such as water supply and sewage systems.
In order to solve the problem of the steel pipe, a corrugated steel pipe having a spiral in the longitudinal direction on the circumference of the pipe is manufactured and released. The corrugated steel pipe may have a shape in which inlets having a substantially soft wave shape are consecutively integrated so that a diameter part is opened or a shape in which substantially -shaped inlets are spaced apart from each other at a significant interval so that the diameter part is opened.
However, the corrugated steel pipe has an advantage in that the corrugated steel pipe is appropriately used, in particular, as a pipe that guides flows of the water supply and sewage systems because the strength is very large due to corrugations formed in a pipe body during use, but several problems due to the corrugations in the steel pipe.
That is, when the fluid flows along the inner diameter of the pipe body, the consecutively formed corrugations severely interfere in the fluid, and as a result, the flow of the fluid is not smooth and in this case, as pressure applied to the inner diameter part of the pipe body rises more than necessary, the fluid leaks through a ruptured portion while the lock-seam connection portion is ruptured and sediment is stacked at the integrated inlets due to the corrugations, and as a result, the fluid is contaminated due to decay of the sediment in long period usage.
Another problem of the corrugated steel pipe in the related art is that since the wave corrugations are consecutively formed in the spiral shape on the circumference of the steel pipe, it is very difficult to bind steel pipes cut with a predetermined length. That is, a flange needs to be fixed to the circumference of corresponding ends so as to bind both ends of the steel pipe and since spiral corrugations are consecutively formed from one end to the other end on the circumference of the waveform steel pipe in the related art, a general type flange cannot be coupled to the outer peripheries of both ends of the steel pipe.
Accordingly, in order to bind the waveform steel pipe in the related art, a special flange considering the spiral corrugations that protrude on the outer periphery of the stele pipe is separately manufactured and thereafter, the corresponding ends of the steel pie need to be bound by using the specially manufactured flange, and as a result, the number of manufacturing processes increase and manufacturing cost increases.
In order to solve the problems of the corrugated steel pipe in the related art, the present inventor has filed Korean Patent Application No. 10-2011-0061698, “Waveform Steel Pipe and the Process of manufacture”. In the present patent, the fluid can smoothly flow in the steel pipe, reinforcing the steel pipe is convenient, and the corresponding ends of the steel pipes can be bound by using a reinforcing ring, but since the reinforcing ring cannot be fixed to the lock-seam portion, an installation section of the reinforcing is limitative, and as a result, it is difficult to bind the corresponding ends of the steel pipes by using the reinforcing ring and it is a little difficult to effectively increase the strength of the steel pipe only by the reinforcing ring.
Therefore, the present inventor has introduced the following technology in order to solve all problems of the waveform pipes in the related art.